Raid Passes are items that can be acquired by spinning the Photo Disc at a Gym. The passes are used by trainers to participate in Raid Battles. Raid Passes can only be obtained by trainers on level 5 and above, because trainers do not have access to gyms before level 5.
There are three types of these passes:
regular Raid Pass,
Premium Raid Pass
and EX Raid Pass.
To see currently owned Raid Passes player can check them out on the item bag page .
The method for obtaining one is currently unknown because this feature is undergoing beta-testing. Select Trainers will receive an EX Raid Pass via their Journal. When the user clicks on the item in the journal, an invitation will be presented and provide information as to when and where the EX Raid Battle will occur.
Many reports indicate that the chosen Gym will be one that has been recently raided by the Trainer in the past couple of days.
Starting on September 20, 2018, when a trainer receives a pass, they may invite one Ultra or Best Friend to participate in the raid with them.
In-game description EX Raid Pass to join a field test for a special Raid Battle. You can use this pass only at the specified limited-time event.